Cutworms or Voles? Diagnosing Stem Damage in Pole Beans

Something bit through pole bean stems 2–3 inches above ground—entire rows killed. The gardener suspected mice, but the pattern suggests cutworms: night-feeding caterpillars that chew stems at soil level. The 10+ years of beans in the same spot? A classic crop rotation violation. Monoculture builds pest populations.

First, confirm the culprit. Cutworms leave clean cuts at or just above soil line. Voles/moles tunnel and may girdle stems. For voles: capsaicin sprays (hot pepper wax) are labeled for beans pre-flowering. Collars work for both: slice paper towel tubes, place around stems at base, push into soil.

Long-term: rotate crops. Beans follow heavy feeders (corn, tomatoes); precede with light feeders or cover crops. Add compost yearly. Encourage predators: ground beetles, birds, parasitic nematodes (Steinernema carpocapsae) for cutworms in moist soil.

Don't replant beans in that spot next year. Break the cycle.